1150 dvor overheads selex rev -tr
DESCRIPTION
informacion util del VOR dopplerTRANSCRIPT
PowerPoint Presentation*
DOPPLER VHF OMNIDIRECTIONAL RANGE BEACON (DVOR)
SELEX Sistemi Integrati Inc.
11300 West 89th Street
Overland Park, KS 66214
T: 1-913-495-2600
*
COURSE OBJECTIVES
Name and locate each major assembly of the 1150 DVOR Equipment, explain the function of each, and explain its contribution to the overall signal flow.
Operate and align the DVOR equipment in accordance with the manufacturer’s specifications.
Recognize out of tolerance conditions and troubleshoot the DVOR equipment to the module, subassembly or Line Replaceable Unit (LRU) level.
Verify and perform hardware and software configuration procedures.
Upgrade operating software of the 1150 DVOR equipment.
Perform ground check procedures and provide ground support for flight checks.
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MODEL 1150 DVOR IN CONTEXT OF GENERAL DVOR THEORY
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Rev -, December 28, 2007
OBJECTIVES OF MODEL 1150 DVOR IN CONTEXT OF GENERAL DVOR THEORY
RF spectrum as seen by the aircraft
The phase relationship of the AM and FM components
How Model 1150 Doppler VOR produces each component
The characteristics of the CSB output from the transmitter
The characteristics of each sideband output from the transmitter
*
The Counterpoise is used for clean reflection of RF pattern
Ring of 48 Sideband Antennas
Carrier Antenna in the center of the ring
The Transmitter is located in the shelter
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VOR ONLY
The “bug” turns the bearing ring to select the direction the pilot wants to be traveling when he arrives at the VOR.
“bug”
Bearing ring
In this case the pilot wants to fly North toward the VOR from the South. He would be on radial 180.
If he is directly south of the VOR, then the needle is centered.
A flag shows that he is flying north “To” the VOR. (The “From” flag would not be visible in this case.)
After he passes over the VOR, the “To” flag disappears and the “From” flag appears.
*
TYPICAL ON-BOARD INDICATORS
VOR AND ILS
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NORTH
AM
FM
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Example
VOR
AM
FM
AM
FM
AM
FM
AM
FM
NORTH
EAST
SOUTH
WEST
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9960
9480
9960
10440
9960
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RF MODULATED BY 30 Hz AUDIO
30 Hz AUDIO FROM
DETECTED RF
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9960 Hz AUDIO WITH
9960 AUDIO
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Rev -, December 28, 2007
VOR SIGNAL FROM PILOT’S POINT OF VIEW (ON SPECTRUM ANALYZER)
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USB
LSB
1
25
26
2
27
3
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Rev -, December 28, 2007
A portion of the 9960Hz signal is formed by mixing the Carrier with the USB in space.
USB
If the sideband antenna were stationary, then the 9960 Hz signal would not vary in frequency.
As the sideband antenna rotates, it approaches or departs the receiver at high velocity.
The Doppler Effect causes the 9960 Hz to deviate above and below its center frequency.
*
The Lower Sideband adds amplitude to the 9960 Hz signal.
USB
LSB
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ODD ANT
EVEN ANT
SIDEBAND 1 (SB3)
SIDEBAND 2 (SB4)
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FIVE RF OUTPUTS FROM THE TRANSMITTER CABINET
CSB – RF at FC, amplitude modulated by 30 Hz + 1020 Hz + VOICE
SIDEBAND 1 – RF at FC-9960Hz, amplitude modulated by rectified sine wave
SIDEBAND 2 – RF at FC-9960Hz, amplitude modulated by rectified cosine wave
SIDEBAND 3 – RF at FC+9960Hz, amplitude modulated by rectified sine wave
SIDEBAND 4 – RF at FC+9960Hz, amplitude modulated by rectified cosine wave
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ALFORD LOOP ANTENNA
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OBJECTIVES OF ALFORD LOOP ANTENNA LECTURE
The physical makeup of the Alford Loop antennas (Carrier and Sideband)
The basic propagation theory of the Alford Loop antenna
Tuning points of the Alford Loop antenna
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TOP VIEW OF CARRIER ANTENNA
Hole for DME antenna mast
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TOP VIEW OF SIDEBAND ANTENNA
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IMPEDANCE MATCHING NETWORK
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THE ALFORD LOOP IS TWO ORTHAGONAL FOLDED DIPOLES.
ONE DIPOLE IS HIGHLIGHTED HERE.
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THE OTHER DIPOLE IS HIGHLIGHTED HERE.
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REMAINING CURRENTS WITH INTERNAL CURRENTS CANCELLED
THE INTERNAL CURRENTS PRODUCE FIELDS OF OPPOSITE AND EQUAL FIELD STRENGTH.
CONSIDER A MOMENT IN TIME. CURRENT FLOWS IN THE PICTURED DIRECTIONS. ASSUMES 180 DEGREES OF PHASE DIFFERENCE BETWEEN THE TWO FOLDED DIPOLES.
THEY CANCEL OUT EACH OTHER, LEAVING ONLY THE FIELDS GENERATED BY THE EXTERNAL ANTENNA SURFACES
THE RESULTING RF PATTERN IS OMNIDIRECTIONAL
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TRANSMITTER CABINET
BLOCK DIAGRAM
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The main physical components of the 1150 DVOR Transmitter Cabinet
The primary function of each module
The flow of RF, Audio, and Control signals
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TRANSMITTER 1
TRANSMITTER 2
RMS
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POWER SUPPLIES
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Directional Coupler provides samples for Power and VSWR measurements
RF Monitor detects samples and provides audio to the Audio Generator for measurement
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Sideband 1 SBO:
CW RF at LSB frequency, modulated 100% by rectified 360 Hz sine wave
360 Sine wave + Sine bi-phase = Rectified sine wave,
which is applied to CW RF to produce SBO
*
Sideband 2 SBO:
CW RF at LSB frequency, modulated 100% by rectified 360 Hz cosine wave
360 Cosine wave + Cosine bi-phase = Rectified Cosine wave,
which is applied to CW RF to produce SBO
*
Sideband 3 SBO:
CW RF at USB frequency, modulated 100% by rectified 360 Hz sine wave
360 Sine wave + Sine bi-phase = Rectified sine wave,
which is applied to CW RF to produce SBO
*
Sideband 4 SBO:
CW RF at USB frequency, modulated 100% by rectified 360 Hz cosine wave
360 Cosine wave + Cosine bi-phase = Rectified cosine wave,
which is applied to CW RF to produce SBO
*
Increases to 48 Vdc if modulation is above 43%.
28 Vdc for remaining circuits.
BCPS 1 powers Transmitter 1
Both BCPSes manage the charge on the single set of batteries.
A second set of batteries may be connected in parallel.
*
The RF is applied to two detectors
Detected RF (audio) is applied to the monitors
*
power levels of CSB and SBO.
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Identification Synchronization to the DME
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PMDT OPERATION
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How to obtain access to the PMDT software
The general layout of the PMDT screen
The use of Print and Copy icons
Memory management
*
default username
and password
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Level 2, only basic controls (On, Off, Transfer, Reset)
Level 3, full control and configuration
Level 4, same as level 3 but adds capability to create usernames and manage other users’ passwords
*
Sidebar – always visible if logged in.
Info and controls of the Sidebar:
Whether there is a maintenance alert
Whether in local mode (must be in local mode to make changes)
Status and connection of each transmitter. These buttons allow for control.
Status of each monitor. Bypass control.
Measurements of the integral monitored parameters.
Status of DMEs (not configured on this screen shot)
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Rev -, December 28, 2007
Print data from this page to a printer connected to this PC.
Copy data from this page to the clipboard. The data can be pasted to other programs (Word Pad, Word, Excel, email, etc.)
*
These values are the ones actually used by the DME
Screen RAM –
Non-volatile Backup Memory
PC storage device
APPLY (F7)
RESET (F8)
System, Print
RMS, Config_Backup
RMS, Config_Restore
Transmitter Cabinet
PMDT PC
Memory Management
*
Rev -, December 28, 2007
Refer to the manual or PMDT software, and examine the following screens:
RMS
Status and Data – Shows condition and measurements of various parameters. These DO NOT include the monitored parameters.
Configuration – Allows the maintenance personnel to select the appropriate operational settings.
A/D Limits defines the “Pre-alarm” limits for the power supplies
Logs – maintains a record of various events. Each tab keeps about 100 records, and rotates the oldest ones off as new ones occur.
Commands – refer to the manual for the definition.
DME Commands refers to a co-located DME; this function gives DME remote control even if the DME has no RMM connection.
*
Configuration
Nominal – Defines the values desired
Offsets and Scale Factors – to calibrate the specific transmitter to produce the Nominal values.
Commands
Ident commands allow the user to force or remove ident for test purposes
*
Integrity – Shows the values and limits of the monitored parameters
Ground Check – Allows technician to run an automatic or semi-automatic ground check, and displays the results.
Certification Test Results and Test Data – Allows the technician to run the listed test, and displays the results.
Standby – displays some of the Transmitters Data fields for the transmitter connected to the dummy load.
Offsets and Scale Factors
Field Detector – adjusts for errors in the detected signal
*
Diagnostics
Power-up results – shows the results of the digital circuitry test performed at the time of power up.
Fault Isolation – Auto diagnostic software.
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HARDWARE CONFIGURATION
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Rev -, December 28, 2007
Pressing this button causes a window to appear with the proper dip switch settings to select the frequency in the window.
*
Dip switch settings for frequency selection
*
E1 – to enable the watchdog, jumper 1-2
There is no E2
E3 –Jumper 3-4 to disable DVOR ground check. Jumper 1-2 to enable DVOR ground check.
E4 – For DVOR application, jumper 3-4
E5 – For DVOR application, jumper 3-4.
Instructor will point out the jumpers at this time.
Serial Interface Hardware configuration
Switch S1
Switches 1, 3, 5, and 8 are set to the ON position
Switches 2, 4, 6, and 7 are set to the OFF position
*
Do NOT jumper E1 to E2. Used only during design.
Do NOT jumper E3 to E4. Used only during Depot maintenance.
E5, E6 and E7 are calibration jumpers set in factory. Do not change them.
Instructor will point out the jumpers at this time.
JP1 set to INT1 position
JP2 is set up during installation, depending on which dialup modem is used, the internal one, or an external one.
Instructor will point out the jumpers at this time.
1A9 Modem CCA Hardware configuration
Software Re-Installation procedures
Instructor will demonstrate the removal and replacement of software chips on a module.
*
CSB TRANSMITTER
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Objectives of CSB Transmitter Lecture
The inputs and outputs of the Frequency Synthesizer and CSB Power Amp
Physical setting and alignment procedures for the Frequency Generator and CSB Power Amp
Test Points of Frequency Synthesizer and CSB Power Amp
Jumper configurations of Frequency Synthesizer and CSB Power Amp
Signal generation and flow of the CSB
*
Rev -, December 28, 2007
*
Table 39. Synthesizer CCA (1A4, 1A20) Controls and Indicators
TP1
Lower Sideband Quadrature Signal. When Sidebands 1 and 2 (1A4, 1A21) are in phase and equal amplitude this signal is a triangular waveform.
TP2
Upper Sideband Quadrature Signal. When Sidebands 3 and 4 (1A5, 1A22) are in phase and equal amplitude this signal is a triangular waveform.
TP3
TP4
TP5
TP6
This test point is available for scope or voltmeter ground
*
Percent modulation stabilization
Built-in power out stability and VSWR protection. In addition, there is VSWR protection by the Audio Generator using the forward and reverse power feedback from the RF Monitor
When the percent modulation is programmed to be more than 43%, supply voltage is increased to 48V
Overtemp (70 C) protection – thermistor mounted on Q5, Q6
*
The LPA Filters out harmonics
Reflected port to measure VSWR
Forward port to measure transmitted power
Feedback for phase and frequency lock
Carrier sample for test point
*
AUDIO GENERATOR
*
The inputs and outputs of the Audio Generator
*
30 Hz (30 %)
Composite output of the Audio Generator
*
Sine wave @ 360 Hz
This sine wave will be rectified in the SB Generator, so there will be 720 “humps” per second.
Sideband 1 and Sideband 2 are 90 degrees (of the 360 Hz signal) out of phase, so the “humps” are 180 degrees out of phase
*
Square wave
Each time the sideband signal reaches zero, the bi-phase changes state
The bi-phase is used in the Sideband Generator to rectify the 360 Hz sine wave.
*
Rev -, December 28, 2007
Sideband Phase DC levels – DC voltage set by the operator in PMDT, to adjust the phase of the sidebands to each other (SB1 to SB2, and SB3 to SB4).
Sideband phasor outputs of the Audio Generator
SB2/4 phase is fixed – it cannot be changed
*
Switching bus to commutator – creates the 30Hz FM sine wave
*
Audio Generator serial communication to RMS
Data to RMS for use in PMDT – measurements of audio and dc analog voltages from the RF Monitor.
DC and audio levels from the RF Monitor.
Voice from automated system (ATIS) or microphone
*
SIDEBAND GENERATION
*
The inputs and outputs of the Sideband Generator
Field alignment procedures for the Sideband Generator
Function of the Isolators
*
Carrier freq Minus 10 KHz
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Carrier freq Minus 10 KHz
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Rev -, December 28, 2007
Sideband 1 (or 3)
Sideband 2 (or 4)
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Rev -, December 28, 2007
Sideband Generator Test Points
Table 310. Sideband Generator (1A5, 1A6, 1A21, 1A22) Controls and Indicators
TP1
This test point is the Sideband 1 (1A5,1A21) or Sideband 3 (1A6,1A22) Dynamic Phase Control Voltage.
TP2
This test point is the Sideband 1 (1A5,1A21) or Sideband 3 (1A6,1A22) Sideband Manual Phase Control Voltage. This is a DC voltage representing the phaser control voltage.
TP3
This test point is the Sideband 1 (1A5,1A21) or Sideband 3 (1A6,1A22) Mean Phase Control Voltage. This is a DC voltage representing the mean (slow) phaser control voltage.
TP4
This test point is the Sideband 1 (1A5,1A21) or Sideband 3 (1A6,1A22 Mean Phase Error Voltage. This is a DC voltage representing the mean (slow) error control voltage. If the control loop is locked this voltage should be nearly 0 volts.
TP5
This test point is the detected output of the Sideband 1 (1A5, 1A21) or Sideband 3 (1A6, 1A22) output. This signal is a rectified 360 Hz waveform in DVOR mode.
*
Rev -, December 28, 2007
Sideband Generator Test Points
Table 310. Sideband Generator (1A5, 1A6, 1A21, 1A22) Controls and Indicators
TP6
This test point is the detected output of the Sideband 2 (1A5, 1A21) or Sideband 4 (1A6, 1A22) output. This signal is a rectified 360 Hz waveform in DVOR mode.
TP7
This test point is the Sideband 2 (1A5,1A21) or Sideband 4 (1A6,1A22 Mean Phase Error Voltage. This is a DC voltage representing the mean (slow) error control voltage. If the control loop is locked this voltage should be nearly 0 volts.
TP8
This test point is the Sideband 2 (1A5,1A21) or Sideband 4 (1A6,1A22 Mean Phase Control Voltage. This is a DC voltage representing the mean (slow) phaser control voltage.
TP9
This test point is the Sideband 2 (1A5,1A21) or Sideband 4 (1A6,1A22 Sideband Manual Phase Control Voltage. This is a DC voltage representing the phaser control voltage.
TP10
This test point is the Sideband 2 (1A5,1A21) or Sideband 4 (1A6,1A22) Dynamic Phase Control Voltage.
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Sideband Generator Test Point 1/10
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Sideband Frequency and Phase lock
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Commutator
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Rev -, December 28, 2007
Isolators are used to redirect reflected energy to a detector circuit to monitor VSWR of sideband antennas
Isolators
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PHASING CONSIDERATIONS
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SIDEBAND GENERATOR
All the RF signals originate from this point.
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SIDEBAND GENERATOR
SIDEBAND GENERATOR
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SIDEBAND GENERATOR
SIDEBAND GENERATOR
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SIDEBAND GENERATOR
SIDEBAND GENERATOR
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SIDEBAND GENERATOR
SIDEBAND GENERATOR
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All five signals must have the same phase in space
SIDEBAND GENERATOR
SIDEBAND GENERATOR
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SIDEBAND GENERATOR
SIDEBAND GENERATOR
Using the PMDT, it is possible to adjust the phase of Sideband 1 to make it equal to Sideband 2.
*
SIDEBAND GENERATOR
SIDEBAND GENERATOR
Using the PMDT, it is possible to adjust the phase of Sideband 3 to make it equal to Sideband 4.
*
Rev -, December 28, 2007
It is not possible to equalize the phases of two different frequencies.
But, consider the Carrier and LSB frequencies.
Their mix in space creates a beat frequency (9960 Hz). This provides half the modulation.
The phase of the beat frequency depends on the relative phase of the two original signals (Carrier and LSB).
*
Now, consider the Carrier and USB frequencies.
Their mix in space also creates a beat frequency (9960 Hz). This provides the other half of the modulation
The phase of this beat frequency also depends on the relative phase of the two original signals (Carrier and USB).
*
Rev -, December 28, 2007
If the phase of the two modulations are the same, then they mix well in space, causing a maximum effect on the carrier (maximum 9960 Hz modulation).
If the phase of the two modulations are not the same, then they don’t mix well in space, causing less than optimum effect on the carrier (low 9960 Hz modulation).
*
Rev -, December 28, 2007
If the phase of the carrier is adjusted, it has the opposite effect on the two beat signals.
Movement of carrier phase both advances one beat signal, and retards the other.
When the 9960 Hz modulation is at its maximum, the Carrier to Sideband Phase is at its optimum value.
*
RF MONITOR
*
The Inputs and Outputs of the RF Monitor
The Test Points of the RF Monitor and their meaning
Adjustment Points of the RF Monitor
*
Each of these inputs is RF
TX 1 Forward power
TX 1 Reflected power
SB1 Reflected power
SB2 Reflected power
SB3 Reflected power
SB4 Reflected power
Each audio output is also seen on the test points.
The RF Monitor contains the Dummy Load for the Standby Transmitter
Sideband forward powers are not detected in the RF Monitor
*
Tüm ayarlar ile, harici wattmetrede okunan deerlere göre PMDT ayarlanr.
All the adjustments are to calibrate the PMDT reading to match an external wattmeter.
TX 1 and 2 Forward and Reflected
Sidebands 1, 2, 3, and 4 Reflected
Note: Sideband forward power PMDT reading is calibrated using R100 on each Sideband Generator
*
LECTURE
MONITORS
*
The fundamental principle of how the composite signals are analyzed
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Monitor Antenna
Dipole antenna located on any radial, at about 300 feet from the center of the counterpoise.
*
Detector 1
Detector 2
Test Generator
Standby Composite
*
DC Level Detector
RF Level
*
FIELD DETECTOR
*
Rev -, December 28, 2007
Detects RF from the field monitor antenna, converts to audio for analysis by the monitors.
Field Detector Lecture
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REMOTE MAINTENANCE SYSTEM (RMS)
*
The purpose of the Lithium battery
Gathers data for interaction with PMDT and RCSU software.
Communicates with other RMS modules through the backplane.
The EEPROM is actually a battery-operated RAM.
Retains its memory as long as the battery is good.
Battery is designed to stay good for 100 years, as long as power remains constantly on.
It takes more than a month of no power to drain the battery
If the CPU CCA is removed from the cabinet, remove the battery jumper to conserve charge.
*
Facilities CCA
Allows CPU μP to send and receive info to/from various discrete and analog lines.
*
Facilities CCA Inputs and Outputs
*
Rev -, December 28, 2007
Summary – Allows CPU μP to communicate with devices that require serial communication.
Audio Generator(s)
Serial Interface CCA
*
Rev -, December 28, 2007
Provides a composite audio signal to apply to the monitors for testing/certification.
It takes several minutes for a signal to form once it is configured.
Test Generator CCA
*
Dedicated line for RCSU
Modem CCA
*
Allows interface between VOR and obsolete 1138 RSCU.
*
Rev -, December 28, 2007
Low Voltage Power Supplies
1A14 supplies the RMS
1A15 supplies Transmitter 1
1A16 supplies Transmitter 2
*
35
37
1
3
5
7
9
11
13
15
17
19
21
23
27
33
31
29
25
39
41
43
45
47
SB1
SB3
36
38
2
4
6
8
10
12
14
16
18
20
22
24
28
34
32
30
26
40
42
44
46
48
SB2
SB4
*
Rev -, December 28, 2007
6.4.3 Cabinet Backplane Connector Adjustment. Use if a replacement module in the RMS does not quite fit into the slot.
6.4.4 Replacing CPU (1A13) CCA. Use this procedure when replacing a CPU CCA. It outlines the procedures for loading the alignment and configuration data into the new CPU.
6.4.5 Update of DVOR Software. This should not be attempted except at the instruction of the factory. New software may not be compatible with old hardware.
6.4.8 Changing the CPU CCA (1A13) Lithium Battery. If the battery fails during Annual Preventive Maintenance (or at any other time), follow this procedure to replace it. This will keep the data intact.
9.7.1 Strapping Battery Charger Power Subsystem (BCPS) for 240 VAC. Use this procedure any time the BCPS is replaced.
9.7.4 Checking the Battery Charger Power Subsystem for 43 or 48 Volts. Use this procedure any time the Main Voltage needs to be checked. Especially check it after the BCPS is replaced, or after a commercial power surge.
Procedures not covered during labs
*
FLIGHT CHECK
*
How to provide ground support for a flight check
What to expect:
Prior to arrival, set the DVOR (and associated DME) with antenna to transmitter 1.
On arrival, a flight crew normally begins a commissioning FC with an orbit. After the orbit, you can expect to hear the following results.
*
Rev -, December 28, 2007
Preparation for Flight Check
Calibrate Transmitters 1 and 2 to produce the value of CSB defined on the Nominal screen, measured with external wattmeter
Calibrate the Sideband Generators so that all eight sidebands have the same power output, measured with external wattmeter
Calibrate the PMDT wattmeter readings
Perform all phasing adjustments (SB1-SB2, SB3-SB4, CSB to Sideband)
Perform the full checkout procedure, paragraph 6.2 of the manual
Adjust the transmitter values to produce ideal monitor values on the PMDT
*
Transmitters, Configuration, Nominal
Adjust for Station Error by putting the number given by the Flight Check crew in the Azimuth Index field.
If using that number increases the error, then change the sign of the index.
For one, the flight crew will announce the Station Error, or Offset.
You will also be told the Spread.
The maximum spread during Flight Check is 4 degrees. There is no corrective action to reduce spread which can be performed during the flight check. All the causes are due to siting.
*
Rev -, December 28, 2007
You will be told the percent modulation of the 9960 Hz signal.
Adjust the 9960 Hz percent modulation by increasing or decreasing the SBO RF level.
Transmitters, Configuration, Nominal
*
Transmitters, Configuration, Offsets and Scale Factors
You will be told the percent modulation of the 30 Hz signal.
Adjust the 30 Hz percent modulation by increasing or decreasing the Scale factor for Transmitter 1.
*
Rev -, December 28, 2007
Once the flight crew has completed a test with Transmitter 1 on antenna, they will ask you to transfer the antenna to Transmitter 2. You will transfer back and forth several times during the Flight Check.
DO NOT adjust any Nominal values when Transmitter 2 is on the antenna.
Transmitters, Configuration, Nominal
*
Rev -, December 28, 2007
If the pre-flight inspection alignment was performed well, then there should be no need to adjust Transmitter 2.
However, if an adjustment is needed, make all adjustments for Transmitter 2 on Transmitters, Configuration, Offsets and Scale Factors screen.
Transmitters, Configuration, Nominal
*
Rev -, December 28, 2007
Once the flight check is complete, and has passed, DO NOT ADJUST ANY MORE TRANSMITTER PARAMETERS. However, it is necessary to adjust the monitor parameters on the Field Detector column.
Azimuth Angle Offset to correct Azimuth Angle.
*
30 Hz Modulation to correct 30 Hz Modulation
9960 Hz Modulation to correct 9960 Hz Modulation
Once the Flight Check has passed, and the monitors are reading ideal values, then maintenance is complete.
Put the controls in normal, clean up, lock up, and have some Scooby snacks.
End of Slide Presentation.
2
S48V
3
M28V
4
S28V
5
M12V
6
S12V
7
M5V
8
S5V
9
M
14
16
-
23
MBCBL
Status
24
MBCPF
25
SBCOT
-
27
SBCBL
Status
28
SBCPF
29
MALM
-
-
RSCU Control Interface CCA
49
ON
OFF
MIC
NORM
ALARM
BYPASS
030364-0001
DOPPLER VHF OMNIDIRECTIONAL RANGE BEACON (DVOR)
SELEX Sistemi Integrati Inc.
11300 West 89th Street
Overland Park, KS 66214
T: 1-913-495-2600
*
COURSE OBJECTIVES
Name and locate each major assembly of the 1150 DVOR Equipment, explain the function of each, and explain its contribution to the overall signal flow.
Operate and align the DVOR equipment in accordance with the manufacturer’s specifications.
Recognize out of tolerance conditions and troubleshoot the DVOR equipment to the module, subassembly or Line Replaceable Unit (LRU) level.
Verify and perform hardware and software configuration procedures.
Upgrade operating software of the 1150 DVOR equipment.
Perform ground check procedures and provide ground support for flight checks.
*
MODEL 1150 DVOR IN CONTEXT OF GENERAL DVOR THEORY
*
Rev -, December 28, 2007
OBJECTIVES OF MODEL 1150 DVOR IN CONTEXT OF GENERAL DVOR THEORY
RF spectrum as seen by the aircraft
The phase relationship of the AM and FM components
How Model 1150 Doppler VOR produces each component
The characteristics of the CSB output from the transmitter
The characteristics of each sideband output from the transmitter
*
The Counterpoise is used for clean reflection of RF pattern
Ring of 48 Sideband Antennas
Carrier Antenna in the center of the ring
The Transmitter is located in the shelter
*
VOR ONLY
The “bug” turns the bearing ring to select the direction the pilot wants to be traveling when he arrives at the VOR.
“bug”
Bearing ring
In this case the pilot wants to fly North toward the VOR from the South. He would be on radial 180.
If he is directly south of the VOR, then the needle is centered.
A flag shows that he is flying north “To” the VOR. (The “From” flag would not be visible in this case.)
After he passes over the VOR, the “To” flag disappears and the “From” flag appears.
*
TYPICAL ON-BOARD INDICATORS
VOR AND ILS
*
NORTH
AM
FM
*
Example
VOR
AM
FM
AM
FM
AM
FM
AM
FM
NORTH
EAST
SOUTH
WEST
*
9960
9480
9960
10440
9960
*
RF MODULATED BY 30 Hz AUDIO
30 Hz AUDIO FROM
DETECTED RF
*
9960 Hz AUDIO WITH
9960 AUDIO
*
Rev -, December 28, 2007
VOR SIGNAL FROM PILOT’S POINT OF VIEW (ON SPECTRUM ANALYZER)
*
USB
LSB
1
25
26
2
27
3
*
Rev -, December 28, 2007
A portion of the 9960Hz signal is formed by mixing the Carrier with the USB in space.
USB
If the sideband antenna were stationary, then the 9960 Hz signal would not vary in frequency.
As the sideband antenna rotates, it approaches or departs the receiver at high velocity.
The Doppler Effect causes the 9960 Hz to deviate above and below its center frequency.
*
The Lower Sideband adds amplitude to the 9960 Hz signal.
USB
LSB
*
ODD ANT
EVEN ANT
SIDEBAND 1 (SB3)
SIDEBAND 2 (SB4)
*
FIVE RF OUTPUTS FROM THE TRANSMITTER CABINET
CSB – RF at FC, amplitude modulated by 30 Hz + 1020 Hz + VOICE
SIDEBAND 1 – RF at FC-9960Hz, amplitude modulated by rectified sine wave
SIDEBAND 2 – RF at FC-9960Hz, amplitude modulated by rectified cosine wave
SIDEBAND 3 – RF at FC+9960Hz, amplitude modulated by rectified sine wave
SIDEBAND 4 – RF at FC+9960Hz, amplitude modulated by rectified cosine wave
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ALFORD LOOP ANTENNA
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OBJECTIVES OF ALFORD LOOP ANTENNA LECTURE
The physical makeup of the Alford Loop antennas (Carrier and Sideband)
The basic propagation theory of the Alford Loop antenna
Tuning points of the Alford Loop antenna
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TOP VIEW OF CARRIER ANTENNA
Hole for DME antenna mast
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TOP VIEW OF SIDEBAND ANTENNA
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IMPEDANCE MATCHING NETWORK
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THE ALFORD LOOP IS TWO ORTHAGONAL FOLDED DIPOLES.
ONE DIPOLE IS HIGHLIGHTED HERE.
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THE OTHER DIPOLE IS HIGHLIGHTED HERE.
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REMAINING CURRENTS WITH INTERNAL CURRENTS CANCELLED
THE INTERNAL CURRENTS PRODUCE FIELDS OF OPPOSITE AND EQUAL FIELD STRENGTH.
CONSIDER A MOMENT IN TIME. CURRENT FLOWS IN THE PICTURED DIRECTIONS. ASSUMES 180 DEGREES OF PHASE DIFFERENCE BETWEEN THE TWO FOLDED DIPOLES.
THEY CANCEL OUT EACH OTHER, LEAVING ONLY THE FIELDS GENERATED BY THE EXTERNAL ANTENNA SURFACES
THE RESULTING RF PATTERN IS OMNIDIRECTIONAL
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TRANSMITTER CABINET
BLOCK DIAGRAM
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The main physical components of the 1150 DVOR Transmitter Cabinet
The primary function of each module
The flow of RF, Audio, and Control signals
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TRANSMITTER 1
TRANSMITTER 2
RMS
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POWER SUPPLIES
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Directional Coupler provides samples for Power and VSWR measurements
RF Monitor detects samples and provides audio to the Audio Generator for measurement
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Sideband 1 SBO:
CW RF at LSB frequency, modulated 100% by rectified 360 Hz sine wave
360 Sine wave + Sine bi-phase = Rectified sine wave,
which is applied to CW RF to produce SBO
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Sideband 2 SBO:
CW RF at LSB frequency, modulated 100% by rectified 360 Hz cosine wave
360 Cosine wave + Cosine bi-phase = Rectified Cosine wave,
which is applied to CW RF to produce SBO
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Sideband 3 SBO:
CW RF at USB frequency, modulated 100% by rectified 360 Hz sine wave
360 Sine wave + Sine bi-phase = Rectified sine wave,
which is applied to CW RF to produce SBO
*
Sideband 4 SBO:
CW RF at USB frequency, modulated 100% by rectified 360 Hz cosine wave
360 Cosine wave + Cosine bi-phase = Rectified cosine wave,
which is applied to CW RF to produce SBO
*
Increases to 48 Vdc if modulation is above 43%.
28 Vdc for remaining circuits.
BCPS 1 powers Transmitter 1
Both BCPSes manage the charge on the single set of batteries.
A second set of batteries may be connected in parallel.
*
The RF is applied to two detectors
Detected RF (audio) is applied to the monitors
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power levels of CSB and SBO.
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Identification Synchronization to the DME
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PMDT OPERATION
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How to obtain access to the PMDT software
The general layout of the PMDT screen
The use of Print and Copy icons
Memory management
*
default username
and password
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Level 2, only basic controls (On, Off, Transfer, Reset)
Level 3, full control and configuration
Level 4, same as level 3 but adds capability to create usernames and manage other users’ passwords
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Sidebar – always visible if logged in.
Info and controls of the Sidebar:
Whether there is a maintenance alert
Whether in local mode (must be in local mode to make changes)
Status and connection of each transmitter. These buttons allow for control.
Status of each monitor. Bypass control.
Measurements of the integral monitored parameters.
Status of DMEs (not configured on this screen shot)
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Rev -, December 28, 2007
Print data from this page to a printer connected to this PC.
Copy data from this page to the clipboard. The data can be pasted to other programs (Word Pad, Word, Excel, email, etc.)
*
These values are the ones actually used by the DME
Screen RAM –
Non-volatile Backup Memory
PC storage device
APPLY (F7)
RESET (F8)
System, Print
RMS, Config_Backup
RMS, Config_Restore
Transmitter Cabinet
PMDT PC
Memory Management
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Rev -, December 28, 2007
Refer to the manual or PMDT software, and examine the following screens:
RMS
Status and Data – Shows condition and measurements of various parameters. These DO NOT include the monitored parameters.
Configuration – Allows the maintenance personnel to select the appropriate operational settings.
A/D Limits defines the “Pre-alarm” limits for the power supplies
Logs – maintains a record of various events. Each tab keeps about 100 records, and rotates the oldest ones off as new ones occur.
Commands – refer to the manual for the definition.
DME Commands refers to a co-located DME; this function gives DME remote control even if the DME has no RMM connection.
*
Configuration
Nominal – Defines the values desired
Offsets and Scale Factors – to calibrate the specific transmitter to produce the Nominal values.
Commands
Ident commands allow the user to force or remove ident for test purposes
*
Integrity – Shows the values and limits of the monitored parameters
Ground Check – Allows technician to run an automatic or semi-automatic ground check, and displays the results.
Certification Test Results and Test Data – Allows the technician to run the listed test, and displays the results.
Standby – displays some of the Transmitters Data fields for the transmitter connected to the dummy load.
Offsets and Scale Factors
Field Detector – adjusts for errors in the detected signal
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Diagnostics
Power-up results – shows the results of the digital circuitry test performed at the time of power up.
Fault Isolation – Auto diagnostic software.
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HARDWARE CONFIGURATION
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Rev -, December 28, 2007
Pressing this button causes a window to appear with the proper dip switch settings to select the frequency in the window.
*
Dip switch settings for frequency selection
*
E1 – to enable the watchdog, jumper 1-2
There is no E2
E3 –Jumper 3-4 to disable DVOR ground check. Jumper 1-2 to enable DVOR ground check.
E4 – For DVOR application, jumper 3-4
E5 – For DVOR application, jumper 3-4.
Instructor will point out the jumpers at this time.
Serial Interface Hardware configuration
Switch S1
Switches 1, 3, 5, and 8 are set to the ON position
Switches 2, 4, 6, and 7 are set to the OFF position
*
Do NOT jumper E1 to E2. Used only during design.
Do NOT jumper E3 to E4. Used only during Depot maintenance.
E5, E6 and E7 are calibration jumpers set in factory. Do not change them.
Instructor will point out the jumpers at this time.
JP1 set to INT1 position
JP2 is set up during installation, depending on which dialup modem is used, the internal one, or an external one.
Instructor will point out the jumpers at this time.
1A9 Modem CCA Hardware configuration
Software Re-Installation procedures
Instructor will demonstrate the removal and replacement of software chips on a module.
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CSB TRANSMITTER
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Objectives of CSB Transmitter Lecture
The inputs and outputs of the Frequency Synthesizer and CSB Power Amp
Physical setting and alignment procedures for the Frequency Generator and CSB Power Amp
Test Points of Frequency Synthesizer and CSB Power Amp
Jumper configurations of Frequency Synthesizer and CSB Power Amp
Signal generation and flow of the CSB
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Rev -, December 28, 2007
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Table 39. Synthesizer CCA (1A4, 1A20) Controls and Indicators
TP1
Lower Sideband Quadrature Signal. When Sidebands 1 and 2 (1A4, 1A21) are in phase and equal amplitude this signal is a triangular waveform.
TP2
Upper Sideband Quadrature Signal. When Sidebands 3 and 4 (1A5, 1A22) are in phase and equal amplitude this signal is a triangular waveform.
TP3
TP4
TP5
TP6
This test point is available for scope or voltmeter ground
*
Percent modulation stabilization
Built-in power out stability and VSWR protection. In addition, there is VSWR protection by the Audio Generator using the forward and reverse power feedback from the RF Monitor
When the percent modulation is programmed to be more than 43%, supply voltage is increased to 48V
Overtemp (70 C) protection – thermistor mounted on Q5, Q6
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The LPA Filters out harmonics
Reflected port to measure VSWR
Forward port to measure transmitted power
Feedback for phase and frequency lock
Carrier sample for test point
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AUDIO GENERATOR
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The inputs and outputs of the Audio Generator
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30 Hz (30 %)
Composite output of the Audio Generator
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Sine wave @ 360 Hz
This sine wave will be rectified in the SB Generator, so there will be 720 “humps” per second.
Sideband 1 and Sideband 2 are 90 degrees (of the 360 Hz signal) out of phase, so the “humps” are 180 degrees out of phase
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Square wave
Each time the sideband signal reaches zero, the bi-phase changes state
The bi-phase is used in the Sideband Generator to rectify the 360 Hz sine wave.
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Rev -, December 28, 2007
Sideband Phase DC levels – DC voltage set by the operator in PMDT, to adjust the phase of the sidebands to each other (SB1 to SB2, and SB3 to SB4).
Sideband phasor outputs of the Audio Generator
SB2/4 phase is fixed – it cannot be changed
*
Switching bus to commutator – creates the 30Hz FM sine wave
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Audio Generator serial communication to RMS
Data to RMS for use in PMDT – measurements of audio and dc analog voltages from the RF Monitor.
DC and audio levels from the RF Monitor.
Voice from automated system (ATIS) or microphone
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SIDEBAND GENERATION
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The inputs and outputs of the Sideband Generator
Field alignment procedures for the Sideband Generator
Function of the Isolators
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Carrier freq Minus 10 KHz
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Carrier freq Minus 10 KHz
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Rev -, December 28, 2007
Sideband 1 (or 3)
Sideband 2 (or 4)
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Rev -, December 28, 2007
Sideband Generator Test Points
Table 310. Sideband Generator (1A5, 1A6, 1A21, 1A22) Controls and Indicators
TP1
This test point is the Sideband 1 (1A5,1A21) or Sideband 3 (1A6,1A22) Dynamic Phase Control Voltage.
TP2
This test point is the Sideband 1 (1A5,1A21) or Sideband 3 (1A6,1A22) Sideband Manual Phase Control Voltage. This is a DC voltage representing the phaser control voltage.
TP3
This test point is the Sideband 1 (1A5,1A21) or Sideband 3 (1A6,1A22) Mean Phase Control Voltage. This is a DC voltage representing the mean (slow) phaser control voltage.
TP4
This test point is the Sideband 1 (1A5,1A21) or Sideband 3 (1A6,1A22 Mean Phase Error Voltage. This is a DC voltage representing the mean (slow) error control voltage. If the control loop is locked this voltage should be nearly 0 volts.
TP5
This test point is the detected output of the Sideband 1 (1A5, 1A21) or Sideband 3 (1A6, 1A22) output. This signal is a rectified 360 Hz waveform in DVOR mode.
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Rev -, December 28, 2007
Sideband Generator Test Points
Table 310. Sideband Generator (1A5, 1A6, 1A21, 1A22) Controls and Indicators
TP6
This test point is the detected output of the Sideband 2 (1A5, 1A21) or Sideband 4 (1A6, 1A22) output. This signal is a rectified 360 Hz waveform in DVOR mode.
TP7
This test point is the Sideband 2 (1A5,1A21) or Sideband 4 (1A6,1A22 Mean Phase Error Voltage. This is a DC voltage representing the mean (slow) error control voltage. If the control loop is locked this voltage should be nearly 0 volts.
TP8
This test point is the Sideband 2 (1A5,1A21) or Sideband 4 (1A6,1A22 Mean Phase Control Voltage. This is a DC voltage representing the mean (slow) phaser control voltage.
TP9
This test point is the Sideband 2 (1A5,1A21) or Sideband 4 (1A6,1A22 Sideband Manual Phase Control Voltage. This is a DC voltage representing the phaser control voltage.
TP10
This test point is the Sideband 2 (1A5,1A21) or Sideband 4 (1A6,1A22) Dynamic Phase Control Voltage.
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Sideband Generator Test Point 1/10
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Sideband Frequency and Phase lock
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Commutator
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Rev -, December 28, 2007
Isolators are used to redirect reflected energy to a detector circuit to monitor VSWR of sideband antennas
Isolators
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PHASING CONSIDERATIONS
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SIDEBAND GENERATOR
All the RF signals originate from this point.
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SIDEBAND GENERATOR
SIDEBAND GENERATOR
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SIDEBAND GENERATOR
SIDEBAND GENERATOR
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SIDEBAND GENERATOR
SIDEBAND GENERATOR
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SIDEBAND GENERATOR
SIDEBAND GENERATOR
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All five signals must have the same phase in space
SIDEBAND GENERATOR
SIDEBAND GENERATOR
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SIDEBAND GENERATOR
SIDEBAND GENERATOR
Using the PMDT, it is possible to adjust the phase of Sideband 1 to make it equal to Sideband 2.
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SIDEBAND GENERATOR
SIDEBAND GENERATOR
Using the PMDT, it is possible to adjust the phase of Sideband 3 to make it equal to Sideband 4.
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Rev -, December 28, 2007
It is not possible to equalize the phases of two different frequencies.
But, consider the Carrier and LSB frequencies.
Their mix in space creates a beat frequency (9960 Hz). This provides half the modulation.
The phase of the beat frequency depends on the relative phase of the two original signals (Carrier and LSB).
*
Now, consider the Carrier and USB frequencies.
Their mix in space also creates a beat frequency (9960 Hz). This provides the other half of the modulation
The phase of this beat frequency also depends on the relative phase of the two original signals (Carrier and USB).
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Rev -, December 28, 2007
If the phase of the two modulations are the same, then they mix well in space, causing a maximum effect on the carrier (maximum 9960 Hz modulation).
If the phase of the two modulations are not the same, then they don’t mix well in space, causing less than optimum effect on the carrier (low 9960 Hz modulation).
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Rev -, December 28, 2007
If the phase of the carrier is adjusted, it has the opposite effect on the two beat signals.
Movement of carrier phase both advances one beat signal, and retards the other.
When the 9960 Hz modulation is at its maximum, the Carrier to Sideband Phase is at its optimum value.
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RF MONITOR
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The Inputs and Outputs of the RF Monitor
The Test Points of the RF Monitor and their meaning
Adjustment Points of the RF Monitor
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Each of these inputs is RF
TX 1 Forward power
TX 1 Reflected power
SB1 Reflected power
SB2 Reflected power
SB3 Reflected power
SB4 Reflected power
Each audio output is also seen on the test points.
The RF Monitor contains the Dummy Load for the Standby Transmitter
Sideband forward powers are not detected in the RF Monitor
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Tüm ayarlar ile, harici wattmetrede okunan deerlere göre PMDT ayarlanr.
All the adjustments are to calibrate the PMDT reading to match an external wattmeter.
TX 1 and 2 Forward and Reflected
Sidebands 1, 2, 3, and 4 Reflected
Note: Sideband forward power PMDT reading is calibrated using R100 on each Sideband Generator
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LECTURE
MONITORS
*
The fundamental principle of how the composite signals are analyzed
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Monitor Antenna
Dipole antenna located on any radial, at about 300 feet from the center of the counterpoise.
*
Detector 1
Detector 2
Test Generator
Standby Composite
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DC Level Detector
RF Level
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FIELD DETECTOR
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Rev -, December 28, 2007
Detects RF from the field monitor antenna, converts to audio for analysis by the monitors.
Field Detector Lecture
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REMOTE MAINTENANCE SYSTEM (RMS)
*
The purpose of the Lithium battery
Gathers data for interaction with PMDT and RCSU software.
Communicates with other RMS modules through the backplane.
The EEPROM is actually a battery-operated RAM.
Retains its memory as long as the battery is good.
Battery is designed to stay good for 100 years, as long as power remains constantly on.
It takes more than a month of no power to drain the battery
If the CPU CCA is removed from the cabinet, remove the battery jumper to conserve charge.
*
Facilities CCA
Allows CPU μP to send and receive info to/from various discrete and analog lines.
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Facilities CCA Inputs and Outputs
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Rev -, December 28, 2007
Summary – Allows CPU μP to communicate with devices that require serial communication.
Audio Generator(s)
Serial Interface CCA
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Rev -, December 28, 2007
Provides a composite audio signal to apply to the monitors for testing/certification.
It takes several minutes for a signal to form once it is configured.
Test Generator CCA
*
Dedicated line for RCSU
Modem CCA
*
Allows interface between VOR and obsolete 1138 RSCU.
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Rev -, December 28, 2007
Low Voltage Power Supplies
1A14 supplies the RMS
1A15 supplies Transmitter 1
1A16 supplies Transmitter 2
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35
37
1
3
5
7
9
11
13
15
17
19
21
23
27
33
31
29
25
39
41
43
45
47
SB1
SB3
36
38
2
4
6
8
10
12
14
16
18
20
22
24
28
34
32
30
26
40
42
44
46
48
SB2
SB4
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Rev -, December 28, 2007
6.4.3 Cabinet Backplane Connector Adjustment. Use if a replacement module in the RMS does not quite fit into the slot.
6.4.4 Replacing CPU (1A13) CCA. Use this procedure when replacing a CPU CCA. It outlines the procedures for loading the alignment and configuration data into the new CPU.
6.4.5 Update of DVOR Software. This should not be attempted except at the instruction of the factory. New software may not be compatible with old hardware.
6.4.8 Changing the CPU CCA (1A13) Lithium Battery. If the battery fails during Annual Preventive Maintenance (or at any other time), follow this procedure to replace it. This will keep the data intact.
9.7.1 Strapping Battery Charger Power Subsystem (BCPS) for 240 VAC. Use this procedure any time the BCPS is replaced.
9.7.4 Checking the Battery Charger Power Subsystem for 43 or 48 Volts. Use this procedure any time the Main Voltage needs to be checked. Especially check it after the BCPS is replaced, or after a commercial power surge.
Procedures not covered during labs
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FLIGHT CHECK
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How to provide ground support for a flight check
What to expect:
Prior to arrival, set the DVOR (and associated DME) with antenna to transmitter 1.
On arrival, a flight crew normally begins a commissioning FC with an orbit. After the orbit, you can expect to hear the following results.
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Rev -, December 28, 2007
Preparation for Flight Check
Calibrate Transmitters 1 and 2 to produce the value of CSB defined on the Nominal screen, measured with external wattmeter
Calibrate the Sideband Generators so that all eight sidebands have the same power output, measured with external wattmeter
Calibrate the PMDT wattmeter readings
Perform all phasing adjustments (SB1-SB2, SB3-SB4, CSB to Sideband)
Perform the full checkout procedure, paragraph 6.2 of the manual
Adjust the transmitter values to produce ideal monitor values on the PMDT
*
Transmitters, Configuration, Nominal
Adjust for Station Error by putting the number given by the Flight Check crew in the Azimuth Index field.
If using that number increases the error, then change the sign of the index.
For one, the flight crew will announce the Station Error, or Offset.
You will also be told the Spread.
The maximum spread during Flight Check is 4 degrees. There is no corrective action to reduce spread which can be performed during the flight check. All the causes are due to siting.
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Rev -, December 28, 2007
You will be told the percent modulation of the 9960 Hz signal.
Adjust the 9960 Hz percent modulation by increasing or decreasing the SBO RF level.
Transmitters, Configuration, Nominal
*
Transmitters, Configuration, Offsets and Scale Factors
You will be told the percent modulation of the 30 Hz signal.
Adjust the 30 Hz percent modulation by increasing or decreasing the Scale factor for Transmitter 1.
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Rev -, December 28, 2007
Once the flight crew has completed a test with Transmitter 1 on antenna, they will ask you to transfer the antenna to Transmitter 2. You will transfer back and forth several times during the Flight Check.
DO NOT adjust any Nominal values when Transmitter 2 is on the antenna.
Transmitters, Configuration, Nominal
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Rev -, December 28, 2007
If the pre-flight inspection alignment was performed well, then there should be no need to adjust Transmitter 2.
However, if an adjustment is needed, make all adjustments for Transmitter 2 on Transmitters, Configuration, Offsets and Scale Factors screen.
Transmitters, Configuration, Nominal
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Rev -, December 28, 2007
Once the flight check is complete, and has passed, DO NOT ADJUST ANY MORE TRANSMITTER PARAMETERS. However, it is necessary to adjust the monitor parameters on the Field Detector column.
Azimuth Angle Offset to correct Azimuth Angle.
*
30 Hz Modulation to correct 30 Hz Modulation
9960 Hz Modulation to correct 9960 Hz Modulation
Once the Flight Check has passed, and the monitors are reading ideal values, then maintenance is complete.
Put the controls in normal, clean up, lock up, and have some Scooby snacks.
End of Slide Presentation.
2
S48V
3
M28V
4
S28V
5
M12V
6
S12V
7
M5V
8
S5V
9
M
14
16
-
23
MBCBL
Status
24
MBCPF
25
SBCOT
-
27
SBCBL
Status
28
SBCPF
29
MALM
-
-
RSCU Control Interface CCA
49
ON
OFF
MIC
NORM
ALARM
BYPASS
030364-0001